Novel approach to combating MERS-CoV
Researchers from Canada and the Netherlands have developed a novel approach to combating a coronavirus named MERS-CoV, the cause agent of Middle East respiratory syndrome (MERS).
MERS is a viral respiratory illness that was first identified in Saudi Arabia in 2012. Until now, the infectious disease has been reported in 27 countries, according to the WHO. But the majority of cases of MERS occurred in Saudi Arabia. Currently, there is no vaccine or specific treatment for MERS-CoV infection. In some regions, the mortality rate from the virus is as high as 41%. To tackle this urgent health threat, many research institutes and pharmaceutical companies are working to develop MERS-CoV vaccines and therapies.
One such group, consisting of scientists at the University of Toronto, the University of Manitoba, and Leiden University Medical Center, focused on the ubiquitin system in human cells that the virus uses to infect and spread in the body. The ubiquitin system, which contains hundreds of proteins, functions in various cellular processes, such as antigen processing, apoptosis, immune response and inflammation, and viral infection. However, many viruses including MERS-CoV produce deubiquitinating (DUB) enzymes that alter the ubiquitin system in a way that suppresses host antiviral innate immune responses. This enables the viruses to multiply and destroy the host tissue.
Using phage-displayed ubiquitin variant (UbV) libraries, the researchers identified inhibitors that effectively and selectively target the DUB enzymes of MERS-CoV. Then they tested the ability of UbVs to inhibit MERS-CoV in cell culture and found that expression of UbVs during MERS-CoV infection resulted in significantly lower virus titers, demonstrating the remarkable potency of UbVs as antiviral agents.
Collectively, the study establishes an approach to produce inhibitors that combat MERS-CoV by using UbVs. Since the approach may also apply to other viruses, findings of the study are of great importance. Moreover, the new approach takes only several weeks to produce viral inhibitors. This is a huge advantage over small-molecule approaches which often take years. The study is published in PLoS Pathogens.